Celgene increasing Acceleron stake

Orphan disease company Acceleron Pharma Inc. (NASDAQ:XLRN) jumped $4.46 (13%) to $38.33 on Wednesday after disclosing in an SEC filing that partner Celgene Corp. (NASDAQ:CELG) is increasing its stake in Acceleron to about 14.8% from 11.3%. Celgene is purchasing 1.1 million Acceleron shares from five of Acceleron's backers -- Advanced Technology Ventures, Flagship Ventures, Polaris Venture Partners, Venrock and Alkermes plc (NASDAQ:ALKS) -- for $47.1 million.

Acceleron and Celgene are co-developing sotatercept ( ACE-011) and ACE-536, which are in Phase II testing to treat beta-thalassemia and myelodysplastic syndromes (MDS). Sotatercept is an activin receptor type 2A (ACVR2A) antagonist, and ACE-536 is a modified ACVR2A fusion protein that inhibits several ligands in the transforming growth factor (TGF) beta superfamily. ...